Update explanation on Helm use case

[somtochiama]

The explanation after the flux create source helm command seems to imply that the command will commit the files to git. This pull request tries to fix that.

Ref: https://cloud-native.slack.com/archives/CLAJ40HV3/p1676320569584019 Signed-off-by: Somtochi Onyekwere [email protected]

[somtochiama]

@stefanprodan I don't know if we want to add an beginning section where we say we expect them to have flux bootstrapped

[stefanprodan]

@somtochiama yes, we need to tell people to bootstrap and link to the install doc.